I live in a house built in the mid 50's. The wiring in the house gives
the term 'jack-leg' a new meaning. I thought you might be interested
in my latest fiasco.
I was trenching through my back yard a couple of months ago when I hit
the underground electrical cable running from my house to my tool
shed. I repaired the cable using direct-burial rated splices. I
installed a GFCI outlet on the circuit where the line leaves the main
brealer box, in case the burried splices begin to fail.
Well lo and behold, the GFCI would trip sporadically, about once a
day, sometimes not for several days, sometimes several times a day. I
dug up my direct burial splice and disconnected it, ensuring that
there was no possible contact between hot and ground.
The problem persisted- the GFCI would trip at seemingly random
intervals. Maybe it's a bad GFCI, I thought. I disconnected the line
coming out of the GFCI outlet and the problem stoped happening,
indicating to me that the GFCI was not the problem here.
So now I have narrowed down the location of the problem to somewhere
between the main breaker box and the spot where I cut the cable with
the trencher. I started crawling around under the house to see if
there was possibly some spot where the insulation on the cable had
been cut and was making intermittant contact with ground. I found a
strange splice in the cable where someone had tapped into this line to
install an additional outlet in the laundry room of the house. I went
up into the laundry room to inspect the outlet. Some idiot thought it
was a good idea to use the ground wire in the outlet as the neutral!
So what happened was that whenever my wife plugged something into this
outlet, current ran from hot to ground, tripping the GFCI. Sometimes
my wife used the outlet every day, sometimes not but once a week.
Needless to say I'm inspecting all of the outlets and wiring in the
house for other stupid wiring tricks.
I have a theory that the nationwide trend toward DIY home improvement
is gradually bringing down the quality of homes in America, and is
creating a lot of safety hazards. People who don't know a thing about
electricity (or know just enough to be dangerous) are creating
situations that could kill someone, even 5 or 10 years down the road.
And it's not limited to electrical- people are running their own gas
lines and making uninformed structural decisions as well.
It is scary to think that the next house you buy may have been owned
by one of the daredevil home improvement hacks that occasionally pop
up in this newsgroup.